It is well-known that conventional hydrofoil boats with totally immersed foils have the drawback, quite similar to that of aircraft, that it is not possible to reduce the flying speed below the minimum lifting speed. In practice, in the case of said hydrofoil boats, this penalizes considerably the operational possibilities of the craft, which is forced in fact to chose between unacceptably high speeds and navigating in displacement conditions.
The use of hyperlifting systems, commonly used for aircraft, has not found practical employment as far as concerns these craft, for many reasons, among which the fact that even using the hydrofoils in a concordant manner (as normal curving foils), the result obtained would be to lose part of the run against efficient and safe control of transverse stability.